I. Field of the Invention
This invention refers to means of removably securing dentures in the mouth of a user. The invention is particularly related to a device and method of employing the device whereby dental posts are secured in two or more teeth having non-parallel root canals and means is provided for arranging the dental posts so that the axis of each is parallel to the other thereby insuring improved anchoring of the denture and improved ease of removing and inserting the denture.
II. Description of the Prior Art
It is known in dentistry to use posts which are permanently anchored to natural teeth to support dentures. An article entitled "Fabrication of a Simple Ball-Socket Attachment" by Joseph T. Quinlivan, D.D.S. in the August, 1974 issue of the Journal of Prosthetic Dentistry, Volume 32, No. 2, and a subsequent article entitled "An Attachment for Overlay Dentures" by Dr. Quinlivan in the September, 1974 issue of the same Journal, Volume 32, No. 3, disclosed a method of attaching dentures. U.S. Pat. No. 2,112,007, issued Mar. 22, 1938 to P. B. Adams for "Anchoring Means for False Teeth" shows a type of ball and socket device. The same general type of device is shown in U.S. Pat. No. 3,085,334 issued Apr. 16, 1963 to J. L. Bischoff et al for a denture attachment. Reference may be also had to U.S. Pat. No. 3,656,236 showing a similar ball-type attachment means.
In addition, Applicant has filed United States Patent application Ser. No. 889,723 on Mar. 24, 1978 entitled "Dental Posts" which disclose improvements in ball and socket type of dental post attachments.
These references disclose the use of a dental post having a segment of a sphere which slips past an o-ring for anchoring dentures but the prior art fails to attack the problem of anchoring dentures in the mouth when posts are anchored in teeth and the posts are not parallel to each other. When a dental post is set in a tooth the first step is to bore a hole in the tooth. This hole must generally follow the root canal of the tooth otherwise there is danger that the hole can penetrate through the side of the tooth, or, the hole can severely weaken the tooth. Natural teeth grow in the mouth in various angles and when two or more spaced-apart natural teeth are employed for anchoring a denture, it is rare that the root canals of the teeth are parallel to each other. This means that manufactured or pre-cast dental posts of the type presently employed, when mounted in holes drilled in natural teeth generally extend in non-parallel relationship. When dentures are inserted in position the recesses in the dentures which receives the posts must accomodate those diverging, non-parallel posts which makes the dentures more difficult to insert and remove, and in addition, impairs the desired objective of a firm, secure fit of the dentures on the dental posts. Prior art requires the fabrication of individual, customized dental posts utilizing the lost wax technique to cast posts that will be parallel when the roots are divergent or convergent, or the optional method of soldering that portion of the posts which extends beyond the root in parallel relationship.